NATURAL HISTORY. 



of concentric layers, and they are deposited in the tissues of the deepest portion of the soft parts, one 

 over the other. The nodular spicules are very characteristic, and in some genera they crowd 

 the softer tissues. Some are knobbed at both ends and along their short stern, and the knobs are 

 like cauliflowers ; others, with four or five crowns of tubercles, are fusiform ; many are club- 



shaped, with longitudinal 



crests, or ai*e spiny, and 

 many are scale-shaped and 

 spinose. 



The great number of 

 genera of this sub-family 

 may be arranged around 

 certain well-marked ones or 

 types. The genus Primnoa 

 has a dendroid stem and long 

 warty or pedunculated knob- 

 like appendages. Each of 

 these contains a polype which 

 is crowded with imbricated 

 scale-shaped spicules. These 

 are movable on their bases. 

 The axis is cylindrical and 

 delicate, and contains some 

 carbonate of lime. They are 

 found in the Atlantic, the 

 Mediterranean, Red Sea, and 

 Pacific Ocean. The genus 

 Gorgonia is a type, and about 

 ten others are grouped with 

 it. The stem contains no 

 carbonate of lime, and is 

 corneous. Gorgonia verru- 

 cosa, of the Mediterranean 

 and English Channel, has a 

 bush-shaped form, or is like 

 an espalier. It branches 

 much, but so as to develop 

 a fan-shaped outline. Some 

 are half an inch and others 



ENLARGED SECTION OF STEM OF COKALLIUM KUBRVM (llED CORAL). 



The polypes are on knob-shaped projections, and have a circular 



one-eighth of an inch in diameter, 

 margin. 



The nearest ally to Gorgonia is the genus Muricea, and it has a softer stem, and the polypes 

 are, as it were, bi-lobed. The Western seas of Amei-ica appear to be its home. Other genera, 

 such as Plexaura, have the polypes sunken in the common soft tissue, which is thick and semi-solid. 

 Its species come from the Antilles, the Canaries, and the Pacific. Leptogorgia, on the contrary, has 

 a thin, almost inembraniform, soft tissue, and the margins of the polypes do not project, and there are 

 no knobs or warts. A flat stem, branching in twos, and forming a plume shape, is characteristic of 

 the genus Lophogorgia; and when the polypes, instead of being placed all around the stem and 

 branches, are restricted to longitudinal lines on either side of a median groove, the forms belong to 

 the genus Pterogorgia. Other genera have a foliaceous-looking stem, some are in straight sword-shaped 

 masses, as Xiphigorgia, and the rest have the branches uniting, so as to form a leafy shape. In 

 Rhipidogorgia the fan shape is very decided, and the soft parts have little warty polypes close to the 

 hard tissue. This genus has many species in the Australian, Pacific, and Atlantic seas. In 

 fact, the world-wide distribution of nearly all these genera is very remarkable. Another type 



